/Engine/Source/Runtime/CoreUObject/Public/UObject/Class.h
If the enumeration is declared as UENUM(Flags), returns a string of the form A | B | C representing set bits A, B, and C. If it is not a bitfield, the result is the same as calling GetNameStringByValue
[FString](API\Runtime\Core\Containers\FString) GetValueOrBitfieldAsString ( int64 InValue ) const